Besnoitia besnoiti and several species of the genus have been reported in a variety of domestic and wild animals in many parts of the world (1, 2, 3, 4, 5). Cutaneous besnoitiosis in cattle has been described as a serious skin condition characterized by painful swellings, alopecia and thickening of the skin (6). It is a chronic, debilitating and occasionally fatal disease with both cutaneous and systemic manifestations (6, 7, 8). Besnoitia cysts and lesions have been observed in the testes, epididymes and blood vessels of bulls (9). The possibility of abortion in cows and sterility in bulls with besnoitiosis has been reported (6). Spontaneous clinical besnoitiosis in cattle with accompanying systemic manifestations has not been fully documented, and the effect of scrotal besnoitiosis on spermatogenesis in bulls has not been previously reported in Nigeria. Case report : Outbreaks of babesiosis, heartwater and suspected cutaneous besnoitiosis were observed in a government farm in the Kano State of Nigeria in March, 1979. The cattle population was over 1500, consisting of exotic (Bos taurus ) and indigenous (Bos indicus ) breeds and their crosses. Clinical Examination : All stages of clinical besnoitiosis were initially observed in 14 bulls and 1 cow in a period of 4 months. The farm was visited bi-weekly for 1 year, during which time 58 bulls and 2 cows showed the lesions. Most of the animals affected with this disease were 3-way crosses of Australian Draughtmaster x Rahaji x Niger Azwak (DM x Rh x AZ). Table 1 summarises the distribution of clinicial cases of besnoitiosis.